The region in question is particularly well adapted to the nesting requirements of the Tennessee Warbler, as we noted them during the above period. Extensive lumbering has removed the greater part of the large growth spruce and balsam timber, which forms the great bulk of the forests of this region, leaving areas of small trees, which, in the older clearings, have grown thickly, and to an average height of ten feet. These are interspersed with areas of more or less open, large timber, and others where the second growth has reached little more than the proportions of somewhat scattered shrubbery. The essentially level surface is frequently scored by slight depressions which form the beds of tiny streams, bordered on either side by boggy ground, dotted with grass tussocks, bushes and small trees, and overspread with a luxuriant growth of moss. Such areas are most numerous in cleared tracts, but not infrequent in the edges and the more open portions of the woods. These are the summer home-sites of the Tennessee Warbler.* * *At the time of our visit to the breeding country, in the middle of June, nest building was completed and full sets of eggs had been laid. Altogether, ten nests were located, all built on the ground in substantially the same general sort of situation, and all but two were found by flushing the bird. The nest is built in the moss, usually in a wet place at the foot of a small bush, and in most cases in woods, somewhat back from the more open part of the clearings. A hollow is dug in the moss, usually beneath an overhanging bunch of grass. The nest is in nearly every case entirely concealed and it is impossible to see it from any view-point without displacing the overhanging grass. Consequently unless the bird is flushed it would be all but impossible to find it. The outer foundation of the nest is of dry grass forming quite a substantial structure. Several nests had wisps of grass stems extending from the front rim, as noted in description of the first nest below. It is lined, usually, with fine dry grass, to which in some instances the quill-like hairs of the porcupine, or white moose hairs, are added, and more rarely still, fine hair-like roots which were not identified.* * *This species seems to be somewhat gregarious. In 1914, in one small clearing, five males were heard singing at the same time. In 1915, in the same clearing, three males were heard singing at once, and two nests were found. In almost every clearing of suitable size at least two pairs of birds were found, the nests being sometimes located rather close together.* * *On the second day of our sojourn, June 19, we visited one of the typical nesting places of this warbler, a boggy cleared swale, with scattering, small second growth, and soon flushed a female from a nest containing six fresh, or practically fresh, eggs. This nest, typical of the majority of those found in both construction and situation, was placed in the side of a small tussock, bedded in moss and completely overhung by the dead grass of the previous year’s growth. The nest was composed entirely of fine, nearly white, dead grass stems. From the front rim protruded outward and downward, a wisp of dead grass tips, lying over the lower grasses in the tussock, and shingled over by the overhanging grass, establishing a continuity of the side of the tussock, thus cunningly adding tothe perfect concealment. A tiny tree and one or two bush shoots grew from the tussock, close to the nest and this feature was typical of the greater number of the nests found.
The region in question is particularly well adapted to the nesting requirements of the Tennessee Warbler, as we noted them during the above period. Extensive lumbering has removed the greater part of the large growth spruce and balsam timber, which forms the great bulk of the forests of this region, leaving areas of small trees, which, in the older clearings, have grown thickly, and to an average height of ten feet. These are interspersed with areas of more or less open, large timber, and others where the second growth has reached little more than the proportions of somewhat scattered shrubbery. The essentially level surface is frequently scored by slight depressions which form the beds of tiny streams, bordered on either side by boggy ground, dotted with grass tussocks, bushes and small trees, and overspread with a luxuriant growth of moss. Such areas are most numerous in cleared tracts, but not infrequent in the edges and the more open portions of the woods. These are the summer home-sites of the Tennessee Warbler.* * *
At the time of our visit to the breeding country, in the middle of June, nest building was completed and full sets of eggs had been laid. Altogether, ten nests were located, all built on the ground in substantially the same general sort of situation, and all but two were found by flushing the bird. The nest is built in the moss, usually in a wet place at the foot of a small bush, and in most cases in woods, somewhat back from the more open part of the clearings. A hollow is dug in the moss, usually beneath an overhanging bunch of grass. The nest is in nearly every case entirely concealed and it is impossible to see it from any view-point without displacing the overhanging grass. Consequently unless the bird is flushed it would be all but impossible to find it. The outer foundation of the nest is of dry grass forming quite a substantial structure. Several nests had wisps of grass stems extending from the front rim, as noted in description of the first nest below. It is lined, usually, with fine dry grass, to which in some instances the quill-like hairs of the porcupine, or white moose hairs, are added, and more rarely still, fine hair-like roots which were not identified.* * *
This species seems to be somewhat gregarious. In 1914, in one small clearing, five males were heard singing at the same time. In 1915, in the same clearing, three males were heard singing at once, and two nests were found. In almost every clearing of suitable size at least two pairs of birds were found, the nests being sometimes located rather close together.* * *
On the second day of our sojourn, June 19, we visited one of the typical nesting places of this warbler, a boggy cleared swale, with scattering, small second growth, and soon flushed a female from a nest containing six fresh, or practically fresh, eggs. This nest, typical of the majority of those found in both construction and situation, was placed in the side of a small tussock, bedded in moss and completely overhung by the dead grass of the previous year’s growth. The nest was composed entirely of fine, nearly white, dead grass stems. From the front rim protruded outward and downward, a wisp of dead grass tips, lying over the lower grasses in the tussock, and shingled over by the overhanging grass, establishing a continuity of the side of the tussock, thus cunningly adding tothe perfect concealment. A tiny tree and one or two bush shoots grew from the tussock, close to the nest and this feature was typical of the greater number of the nests found.
They give the measurements of four nests; the outside diameter varied from 3 to 4 inches, the inside diameter from 11⁄8to 2 inches, the outside depth from 2 to 31⁄4, and the inside depth from 11⁄8to 11⁄2inches. What nests I have seen, in collections, all appeared much flatter than the above measurements indicate, but they were probably flattened in transit. All that I have seen seemed to consist entirely of very light, straw-colored grass rather lightly arranged. Some observers mention moss in the composition of the nest, but the nests are evidently made in the moss and not of it.
Dr. Paul Harrington mentions in his contributed notes four nests that he found near Sudbury, Ontario: “The nests were all similarly situated in a clump or mound of sphagnum, well arched so that to obtain a full view of the nest it was necessary to part the sphagnum, in shaded areas on the borders of black spruce bogs. These, and others I have examined, have always been constructed entirely of fine straw-colored grasses, whereas in those of the Nashville warbler a few hairs or gold-threads were generally incorporated in the structure.”
Philipp and Bowdish (1919) record in a later paper the finding of a number of additional nests in New Brunswick, and say: “The experience of the past two years has demonstrated that while the boggy ground nesting, previously described, is the really typical and by far the most common form, not a few of these birds nest on higher and dryer ground. One such nest, found June 24, 1918, was well up on a steep hillside, in rather open woods, on fairly dry ground, utterly devoid of moss and grass cover. It was built among a thick growth of dwarf dogwood, and under a tiny, crooked stemmed maple sapling, very well concealed, and was rather more substantially built than the average nest of this species.”
The nesting history of the Tennessee warbler would not be complete without mentioning two authentic records made in 1901. J. Parker Norris, Jr. (1902), reported receipt of a set of four eggs, collected by Major Allan Brooks on June 15, 1901, at Carpenter Mountain, Cariboo, British Columbia. This is apparently the first authentic set of eggs ever taken, as those mentioned above by Professor Cooke were taken a few days later. In this far western locality, the birds “generally frequented the clumps of aspen trees and Norway pines, where the ground was covered with a thick growth of dry pine grass.” Major Brooks found several other nests in the same locality, and says in his notes: “The nests were always on the ground, sometimes at the foot of a small service berry bush or twig. They were all arched over by the dry pine grass of the preceding year, this year’s growth having just well commenced.”
The Fort Smith nests, referred to by Professor Cooke, were recorded by Edward A. Preble (1908) as follows:
Nests containing eggs were found by Alfred B. Preble on June 20 and 27, the eggs, five in number, being fresh in each instance. The first nest was embedded in the moss at the foot of a clump of dead willows near the edge of a dense spruce forest. It was rather slightly built of dead grass with a lining of the same material, and was protected from above by the overhanging bases of the willows, and by the strips of bark which had fallen from them, so that the nest could be seen only from the side. The second nest was more bulky, was composed outwardly of shreds of bark, coarse grass, andEquisetumstems, and was lined with fine grass. It was placed on the ground beneath a small fallen tree, in a clearing which had been swept by fire a year or two previously.
W. J. Brown, of Westmount, Quebec, tells me that he and L. M. Terrill in an hour found 16 nests of this warbler in a corner of a sphagnum bog, and, “there must have been about 100 pairs nesting in this ideal spot at the time.”
Eggs.—The Tennessee warbler lays large sets of eggs, from four to seven, with sets of six common. Philipp and Bowdish (1919) state, “it appears that more full layings of six eggs are to be found than of five.”
The eggs are ovate to short ovate and have only a slight luster. The ground color is white or creamy white, and the markings, in the form of speckles and small spots, are in shades of “chestnut” and “auburn,” sometimes intermingled with “light vinaceous-drab.” On some the markings are well scattered over the entire surface while on others they are concentrated at the large end, often forming a loose wreath. Only occasionally do the spots assume the proportions of blotches. The measurements of 50 eggs average 16.1 by 12.4 millimeters; the eggs showing the four extremes measure17.8by 12.7, 16.8 by13.1,14.8by 12.3, and 15.8 by11.4millimeters (Harris).
Young.—Nothing seems to have been recorded on the period of incubation, which is performed by the female alone. Nor do we know anything about the care of the young or their development.
Plumages.—Dr. Dwight (1900) says that the young Tennessee warbler in juvenal plumage, in which the sexes are alike, is similar to the young Nashville warbler in similar plumage but lacks the brownish cast and has a faint transocular stripe. He describes it as “above dull grayish olive-green, the rump brighter. Wings and tail clove-brown, the primaries whitish edged, the secondaries, tertiaries and wing coverts greenish edged with two yellowish white wing bands. Below grayish buff rapidly fading when older to a greenish gray; abdomen and crissum pale straw-yellow. Trace of ducky transocular streak.”
The incomplete postjuvenal molt, involving the contour plumage and the wing coverts, but not the rest of the wings or the tail, begins about the middle of July. This produces the first winter plumage,in which the young male is “above, bright olive-green, gray tinged on the pileum. Below, olive-yellow darker on the flanks, the abdomen and crissum white. Superciliary line and orbital ring buff. Transocular streak dull black.” The young female “differs from the male in having the lower parts more washed with olive-green.” Young and old birds are now practically indistinguishable.
Dickey and van Rossem (1938) say that the prenuptial molt “begins in late February and is not finished before about the middle of March. The molt involves most of the anterior body plumage, but progresses so slowly that this species never has the ragged ‘pin-feathered' appearance so often seen inDendroica aestivaat the spring molt.” Dr. Dwight noticed the beginning of this molt as early as January 14. He says it “involves chiefly the head, chin and throat. The ashy gray cap is acquired, the chin, throat, and superciliary line become white, the throat is tinged with cream-buff and the transocular streak black. The yellow tints of the feathers retained below are lost by wear.” In the female, this molt is less extensive than in the male, and “the crown never becomes, even in later plumages, as gray as that of the male, but always has a brown or greenish tinge.”
Subsequent molts consist of a complete postnuptial in July and a partial prenuptial molt in late winter and early spring as in the young bird.
Food.—Bowdish and Philipp (1916) sent four stomachs of birds collected in June to the U. S. Biological Survey for analysis. One of these was empty. Of the other three, one contained 8 small caterpillars (Tortricidae), 35 percent; dipterous fragments, 23 percent; a small spider, 2 percent; and scalelike fragments (perhaps of some catkin), 40 percent. Another held a camponotid ant, 16 percent; at least 78 small caterpillars (Tortricidae), 75 percent; a snail (Vitrea hammoides), 4 percent; and unidentified vegetable fragments, 5 percent. The other contained 3 lampyrids (nearPodabrus), 8 percent; a small coleopterous (?) larva, 3 percent; about 15 small caterpillars (as above), 25 percent; a neuropterous insect (apparently a caddis fly), 50 percent; 2 small spiders, 14 percent; and a trace of unidentified vegetable matter.
Several observers have complained that Tennessee warblers do considerable damage to grapes, and this is undoubtedly true. W. L. McAtee (1904), while investigating the damage done by this and the Cape May warbler, found that—
in the arbor under observation, which was a small one, scarcely a grape and not a cluster was missed. The damage, however, was inconsiderable as the birds did not commence to use their appropriated share of the crop until the owner had taken all he desired.* * *Both species were constantly busy catching insects on the vines, and on a walnut and some appletrees near by. Frequently, however, they dashed into the vines and thrust their bills quicklyinto a grape. Sometimes they withdrew them quickly; again they poked around in the interior of the grape a little, and always after these attacks, they lifted their heads as in drinking. This action suggested a reason for piercing the grapes, that I am satisfied is the true one, that is, the obtaining of liquid refreshment.
A supply of available drinking water for the birds, might help to protect the grapes. And, as the warblers feed on insects that seriously damage the grapevines, the good work they do may compensate for the grapes that they damage. The stomach of one Tennessee warbler examined by Mr. McAtee contained aTyphlocyba comes, an especial pest of the grape, a destructive jassid or leafhopper, 6 caterpillars which were doing all in their power to eat up the leaves remaining on the vines, 2 spiders, a bug (Corizus), a weevil, and one parasitic hymenopteron (the only insect that was not harmful).
S. A. Forbes (1883) found that a stomach taken from an orchard infested by canker-worms contained about 80 percent of these destructive larvae and about 20 per cent beetles. Professor Aughey (1878) observed these warblers catching young locusts in Nebraska. Clarence F. Smith adds, in some notes sent to me, that “in the fall, during migration time, Tennessee warblers often glean their food from dense patches of such weeds as sunflower, goldenrod, and ragweed,” and that “sumac, poison ivy, and other berries are sometimes eaten in small quantity.”
F. H. King (1883) has considerable to say about the damage done to Delaware and Catawba grapes in Wisconsin; as soon as they are wounded, they are attacked by ants, bees, and flies and soon destroyed. But he thinks the service rendered more than compensates for the harm done. He refers to the feeding habits of the Tennessee warbler as follows:
It is very dexterous in its movements, and obtains the greater part of its food upon and among the terminal foliage of trees. Titmouse-like, it often swings pendant from a leaf while it secures an insect which it has discovered. Small insects of various kinds, not especially attractive to larger birds, are destroyed by this species in large numbers; and its slender, acute bill serves it much better in picking up these forms than a heavier, more clumsy one could.* * *Of thirty-three specimens examined, two had eaten two very small hymenoptera (probably parasitic); seven, thirteen caterpillars; three, fifteen diptera; six, thirteen beetles; three, forty-two plant-lice, among which were two specimens of the corn plant-louseAphis maidis(?); three, thirty-five small heteroptera, .09 of an inch long; and one, eleven insect eggs.
Alexander F. Skutch has sent me the following interesting notes on the feeding habits of the Tennessee warbler in Central America: “I was surprised to find last month [March] that these warblers were visiting my feeding shelf on the guava tree in the yard. About the only food I ever serve to the birds on this table is bananas and occasionally plantains; and my chief guests are tanagers of about half a dozen brilliantkinds, a few finches, honeycreepers, and wintering Baltimore orioles. But the Tennessee warblers soon formed the habit of visiting the table and sharing the food with the bigger resident birds.
“Some seemed to linger in the vicinity much of the day, making frequent visits to the board and each time eating liberal portions of banana or the somewhat harder ripe plantain. They were intolerant of each other, and one individual would not let a second alight on the board until it had finished its own meal, although there was plenty of room and plenty of food for all. I have noticed also that the Tennessee warblers chase each other as they forage among the trees in wintering flocks. I cannot recall ever having seen any other wood warbler eat banana.
“Last November 14 a Tennessee warbler behaved most surprisingly. The grass in the yard had grown very long, and I had it cut with a machette. Late in the afternoon, after the usual rain, a lone Tennessee warbler flew down on the fallen grass and began to hop over it, catching small insects.
“It also entered the uncut grass, about a foot high, and disappeared momentarily amidst it. Twice driven up by passing people, each time it promptly returned to the grass. Its third visit to the cut grass was longest. While I stood quietly watching, it hopped deliberately about, much in the manner of a house wren, and gathered an abundant harvest from the fallen herbage. Once it found a caterpillar about an inch long, which it carefully bruised in its mandibles before swallowing it. The warbler was amazingly bold, and hopped over the grass within a yard of my feet, and allowed me to follow closely as it moved away. Early the following morning, and again at the close of the day, the warbler foraged over the lawn in the same fashion. In the evening, it continued to creep slowly over the mown grass and after all other birds had disappeared into their roosts, and the light was becoming too dim to see it clearly.”
Behavior.—Much of the behavior of the Tennessee warbler has been mentioned above, and there is little more to be said. It is a very close sitter on its nest, when incubating, and has been caught there by throwing a hat or a net over it; but, when flushed, it is rather shy about returning to it, usually making its demonstrations of protest by flitting about at a safe distance and nervously uttering a sharpchip.
The Prebles (1908) witnessed a rather remarkable flight behavior at Fort Resolution, Mackenzie:
During the forenoon of June 25, an extremely windy day, we observed a remarkable movement of these warblers. They came from the northward, flying over the point of land on which the fort is built In loose flocks of from 10 to 20 individuals. After passing the point, they either struck out directly across the bay or skirted the shore, in either case having to face a strong southeast wind. Some paused a few moments among the low bushes on the point, but the slightestalarm started them off. The flight lasted over two hours, and, during this time, upward of 300 birds were seen from our camp. Two specimens, a male and a female, were collected. The ovaries of the female contained eggs only slightly developed.
Voice.—Aretas A. Saunders contributes the following: “The song of the Tennessee warbler is a rapid series of short, loud, unmusical notes. It has been compared to the song of the chipping sparrow, but it varies more in pitch, time, and loudness, and is distinctly in two or three parts. To my ear it is much more like the chippering of a chimney swift.
“In 35 records of this song, the number of notes varies from 9 to 25, the average being 17. Only one song has a true trill in it, that is, notes so rapid that they cannot be counted. Each song is of either two or three parts, each part composed of a series of notes on the same pitch and in uniform rhythm. The parts differ from each other in pitch, time, or loudness. In a number of songs, one of the parts is a repetition of 2-note phrases. Loudness generally increases to the end of the song, but sometimes the reverse is true. Some songs rise in pitch to the end and others fall; my records are about evenly divided in this matter. A typical three part song would be something like
tit it it it it it it pita pita pita pita pita chit chitchitchit chit.
“Pitch varies from G‴ to E‴′, or four and a half tones. Single songs vary from half a tone to three and a half tones, averaging one and a half. The length of songs varies from 14⁄5to 31⁄5seconds. An individual bird may sing a dozen different variations of the song in a short time. On the other hand, I have heard three birds in one tree singing alternately, the songs of all three being exactly alike so far as my ear could determine.”
Francis H. Allen gives me his impression of the song as follows: “The song bears some resemblance to that of the Nashville warbler, but is easily distinguished. I have written it
wi-chip wi-chip wi-chip wi-chip, wi-chip wi-chip chip chip chip chip chip chip chip.
The higher notes in the middle sometimes appear to be monosyllables, and they are sometimes omitted. The series ofchipsat the end are very emphatic, and the last one is perhaps accented somewhat. All the notes are staccato.”
Various other renderings of the song have appeared in print, but they all give the same impression of a variable, loud, striking song which, once learned, can be easily recognized. The bird is a very persistent singer rivaling the red-eyed vireo in this respect. Bowdish and Philipp (1916) write: “As a basis for estimating the frequency of song repetition, counts were kept on three singing birds for a period of 5 minutes each, with a result of 32, 36, and 22 songs, respectively,within the period. In one instance, a bird was observed to sing while on the wing, repeating the song twice in the course of a short flight.” Albert K. Brand (1938) found the pitch of the Tennessee warbler’s song to be well above the average, the approximate mean count being 6,600 vibrations per second, the highest note about 9,150 and the lowest 4,025; this compares with an approximate mean of 8,900 vibrations per second for the black-poll warbler, and about 4,000 for the average passerine song.
Field marks.—The Tennessee warbler has no prominent wing-bars and no very conspicuous field marks. It might be mistaken for one of the small vireos, but its bill is much more slender and acute. The male has a gray crown, a light line over the eye, and a dusky line through it; the upper parts are bright olive-green and the under parts grayish white. The female has a greener crown and more yellowish under parts. For more details, see the descriptions of plumages.
Fall.—The fall migration starts early in August, but is quite prolonged, many birds lingering in the northern States until early in October and in the southern States all through that month. During some seasons and at certain places the Tennessee warbler is exceedingly abundant, sometimes far outnumbering any other species, but it is very variable in its abundance.
Mr. Trautman (1940) says that at Buckeye Lake, Ohio, “during some years not more than 20 individuals could be recorded in a day in the southward migration, nor more than a 100 in the season. In other years the bird rivaled the Myrtle Warbler in numbers, and as many as 1,000 individuals could be seen in a day and several thousands during a migration.* * *Throughout the southward migration the species did not confine itself to the upper sections of the taller trees as in spring, but was found in almost equal numbers in smaller trees and brushy thickets, in bushes and saplings along fence rows, and in weedy fields.”
Professor Cooke (1904) says of the fall migration route: “The principal line of migration is from the Mississippi Valley across the Gulf of Mexico to Mexico and Central America. The eastern part of this route probably extends from the southern end of the Alleghenies across northwestern Florida to the coast of Yucatan and Honduras.” A. H. Howell (1932), however, gives several records for central and southern Florida, and says: “In autumn, Weston reports a large migration on October 26 and 27, 1925, when 31 birds were killed at the lighthouse near Pensacola on the two nights, and large numbers seen on the morning of October 26 in vacant lots in the city.”
Dickey and van Rossem (1938) say of the migration in El Salvador:
During the fall migration of 1925, Tennessee warblers arrived in the vicinity of Divisadero on October 13. No advance guard, that is, individuals arrivingahead of the main flights, was observed in this case. On the above-mentioned date they were suddenly found to be present in numbers, and from then on were common in every lowland or foothill locality visited. In point of relative abundance this was by far the most common warbler (resident or migratory) throughout the coastal plain and in the foothills, but it was greatly outnumbered byDendroica virensabove 3,000 feet.The manner of occurrence was usually as small flocks of six or eight or even twenty or more birds. These combined with several other species to make up larger flocks which worked ceaselessly through the crown foliage of low, semi-open woodland. However, many were found even in the tall, dense swamp forests along the coast and also in the oak woods on Mt. Cacaguatique.
During the fall migration of 1925, Tennessee warblers arrived in the vicinity of Divisadero on October 13. No advance guard, that is, individuals arrivingahead of the main flights, was observed in this case. On the above-mentioned date they were suddenly found to be present in numbers, and from then on were common in every lowland or foothill locality visited. In point of relative abundance this was by far the most common warbler (resident or migratory) throughout the coastal plain and in the foothills, but it was greatly outnumbered byDendroica virensabove 3,000 feet.
The manner of occurrence was usually as small flocks of six or eight or even twenty or more birds. These combined with several other species to make up larger flocks which worked ceaselessly through the crown foliage of low, semi-open woodland. However, many were found even in the tall, dense swamp forests along the coast and also in the oak woods on Mt. Cacaguatique.
Winter.—Dr. A. F. Skutch has contributed the following account: “The Tennessee warbler winters in Central America in vast numbers. Coming later than many other members of the family, the first individuals appear in mid-September; but the species is not abundant or widely distributed until October. During the year I passed on the Sierra de Tecpán in west-central Guatemala a single Tennessee warbler appeared in the garden of the house, at 8,500 feet, on November 7 and despite frosty nights lingered into December. On November 19, 1935, I saw one on the Volcán Irazú in Costa Rica at 9,200 feet—the highest point at which I have a record of the species. At the other extreme I found a few of these adaptable birds among the low trees on the arid coast of El Salvador in February and among the royal palms at Puerto Limón, on the humid coast of Costa Rica, in March. But Tennessee warblers are most abundant as winter residents at intermediate altitudes, chiefly between 2,000 and 6,000 feet above sea-level. From 3,000 to 5,000 feet they often seem to be the most abundant of all birds during the period of their sojourn. They travel in straggling flocks and form the nucleus of many of the mixed companies of small, arboreal birds. At times ‘myriads’ is the only term that seems apt to describe their multitudes.
“I think ‘coffee warbler’ would be a name far more appropriate than Tennessee warbler for this plainly attired little bird; it was merely a matter of chance that Alexander Wilson happened to discover the species in Tennessee rather than at some other point on its long route from Canada to Central America; but the warblers themselves manifest a distinct partiality to the coffee plantations. The open groves formed by the shade trees, whose crowns rarely touch each other, yet are never far apart, seem to afford just the degree of woodland density that they prefer. It matters not whether these trees are Grevilleas from Australia with finely divided foliage, or Ingas with large, coarse, compound leaves, or remnants of the original forest—a mixture of many kinds of trees with many types of foliage: from Guatemala to Costa Rica the Tennessee warblers swarm in the coffee plantations during the months of the northern winter and are often the most numerous birds of any species among the shade trees. Possibly theymay at certain times and places be as multitudinous in the high forest as in the plantations. Although I have never found them so, the negative evidence must not be allowed to weigh too heavily, for such small, inconspicuous birds, devoid of bold recognition marks, are not easy to recognize among the tops of trees over a hundred feet high.
“Tennessee warblers are fond of flowers, especially the clustered heads of small florets of the Compositae and Mimosaceae, and of the introduced Grevillea that sometimes shades the coffee plantations. They probe the crowded flower clusters, perhaps seeking small insects lurking there rather than nectar. The white, clustered stamens of the Inga—the most generally used shade tree of the coffee plantations—are especially attractive to them. Local movements within their winter range appear to be controlled by the seasonal abundance of flowers. So, in the valley of the Río Buena Vista in southern Costa Rica, at an altitude of about 3,000 feet, I found Tennessee warblers very abundant during December and January. Here they flocked not only in the forest and among the shade trees of the little coffee groves, but also in great numbers through the second-growth thickets that filled so much of the valley, where at this season there was a profusion of bushy composites with yellow or white flower-heads, and of acacia-like shrubs (Calliandra portoricensis) with long, clustered, white stamens. But during February, the third dry month, the thickets became parched and flowered far more sparingly. Now the Tennessee warblers rapidly declined in numbers, and before the end of the month disappeared from the valley. During the following year, which in its early quarter was far wetter, a number remained through March, and a few well into April.
“Tennessee warblers pluck the tiny, white protein corpuscles from the brown, velvety bases of the long petioles of the great-leafed Cecropia trees, taking advantage of these dainty and apparently nutritious tid-bits when the usual Azteca ants fail to colonize the hollow stems; for only on trees free of ants does this ant-food accumulate in abundance.
“While the Tennessee warbler departs during February from some districts where it is common in midwinter, it remains until April in regions where the dry season is not severe. After the middle of April it is only rarely seen in Central America; and there appears to be no record of its occurrence in May.”
DISTRIBUTION
Range.—Canada to northern South America.
Breeding range.—The Tennessee warbler breedsnorthto southwestern Yukon (Burwash Landing and the Dezadiash River); southern Mackenzie (Mackenzie River below Fort Wrigley, lowerGrandin River, and Pike’s Portage); northeastern Manitoba (Churchill and York Factory); central Quebec (Fort George, Lake Mistassini, and Mingan); and possibly southern Labrador (Hawkes Bay).Eastto southeastern Labrador (Hawkes Bay); central Newfoundland (Lamond and Gaff Topsail).Southto central Newfoundland (Gaff Topsail); Nova Scotia (Wolfville); southern New Brunswick (Grand Manan); northern and central western Maine (Mount Katahdin, Livermore, and Lake Umbagog); north-central New Hampshire (Mount Washington); south-central Vermont (Rutland); possibly northwestern Massachusetts (Hancock); southern New York (Slide Mountain); southern Ontario (Ottawa, North Bay, and Biscotasing; probably occasionally farther south); west-central Michigan (Duck Lane); probably northern Wisconsin (Plum Lake); northern Minnesota (Tower, Cass Lake, and Warren); southwestern Manitoba (Margaret and Aweme); central Saskatchewan (Emma Lake; has been found in the breeding season at Indian Head, Old Wives Creek, and Maple Creek); southern Alberta (Flagstaff, Red Deer, and Banff); and south-central British Columbia (150 Mile House and Kimquit).Westto western British Columbia (Kimquit, Hazelton, Telegraph Creek, and Atlin); and southwestern Yukon (Dezadiash River and Burwash Landing).
Winter range.—In winter the Tennessee warbler is foundnorthto central Guatemala (Volcán de Santa María, Cobán, and Gualán).Eastto eastern Guatemala (Gualán); northeastern El Salvador (Mount Cacaguatique); eastern Nicaragua (Río Escondido); eastern Costa Rica (Puerto Limón); eastern Panamá (Barro Colorado and Permé); northern Colombia (Santa Marta region); and northern Venezuela (Caracas).Southto northern Venezuela (Caracas and Mérida); and northwestern Colombia (Concordia).Westto western Colombia (Concordia and Antioquia); Panamá (Paracaté); Costa Rica (El General and Liberia); El Salvador (Puerto de Triunfo); and Guatemala (Tecpán and Volcán de Santa María). It has also been found to the first of January (possibly delayed migration) at Knoxville (1936) and at Nashville (1935), Tenn.; and one wintered (1934-35) in Cameron County, Tex.
Migration.—Late dates of departure from the winter home are: Colombia—Miraflores, April 19. Costa Rica—San Isidro del General, April 30. El Salvador—San Salvador, April 25. Guatemala—Livingston, April 8. Chiapas—Tixtla Gutiérrez, May 8. Tamaulipas—Gómez Farías, April 27.
Early dates of spring arrival are: Cuba—Habana, April 8. Florida—Sandy Key, April 13. Georgia—Athens, April 13. District of Columbia—Washington, May 2. West Virginia—French Creek, April 20. Pennsylvania—McKeesport, April 27. New York—Corning,May 3. Massachusetts—Northampton, May 8. Maine—Waterville, May 11. New Brunswick—Petitcodiac, May 19. Quebec—Quebec, May 19. Louisiana—Avery Island, April 6. Arkansas—Winslow, April 8. Tennessee—Memphis, April 9. Kentucky—Bowling Green, April 19. Indiana—Bloomington, April 12. Ohio—Columbus, April 25. Michigan—Ann Arbor, April 21. Ontario—Ottawa, May 12. Missouri—Columbia, April 22. Iowa—Sigourney, April 25. Wisconsin—St. Croix Falls, April 25. Minnesota—Clarissa, April 30. Kansas—Winfield, April 19. Nebraska—Red Cloud, April 18. South Dakota—Vermillion, May 1. North Dakota—Fargo, May 1. Manitoba—Margaret, May 3. Colorado—Estes Park, May 14. Wyoming—Torrington, May 12. Montana—Great Falls, May 9. Alberta—Belvedere, May 1. British Columbia—Carpenter Mountain, Cariboo, May 15; Atlin, May 26.
Late dates of spring departure of transients are: Cuba—Habana, May 5. Florida—Fort Myers, May 15. Alabama—Melville, May 3. Georgia—Athens, May 7. North Carolina—Chapel Hill, May 3. Virginia—Falls Church, June 3. District of Columbia—Washington, June 3. Pennsylvania—Warren, May 30. New York—Rochester, June 6. Massachusetts—Beverly, June 3. Vermont—Wells River, June 5. Louisiana—Shreveport, May 15. Mississippi—Oxford, May 15. Arkansas—Delight, May 20. Tennessee—Nashville, May 21. Illinois—Lake Forest, June 3. Ohio—Toledo, June 5. Michigan—Houghton, June 7. Ontario—Toronto, June 7. Missouri—Columbia, May 31. Iowa—Sioux City, June 6. Wisconsin—Racine, June 4. Minnesota—St. Paul, June 1. Kansas—Lawrence, May 24. Nebraska—Omaha, May 28. South Dakota—Faulkton, June 5.
Late dates of fall departure are: British Columbia—Atlin, July 26; 16-mile Lake, Cariboo, August 28. Alberta—Glenevis, September 13. Montana—Fortine, September 11. Wyoming—Laramie, October 5. Saskatchewan—Wiseton, September 29. Manitoba—Aweme, October 3. North Dakota—Fargo, October 8. South Dakota—Arlington, October 8. Nebraska—Lincoln, October 14. Kansas—Lawrence, October 22. Oklahoma—Fort Sill, October 19. Minnesota—Hutchinson, October 11. Wisconsin—Madison, October 19. Iowa—National, October 17. Missouri—St. Louis, October 19. Michigan—Ann Arbor, October 30. Ontario—Port Dover, October 10. Ohio—Columbus, October 31. Illinois—Evanston, October 28. Tennessee—Nashville, October 23. Arkansas—Jonesboro, October 19. Louisiana—New Orleans, November 8. Mississippi—Gulfport, November 12. Quebec—Montreal, September 28. Vermont—Wells River, September 29. Massachusetts—Harvard, October 1. New York—Rhinebeck, October 14. Pennsylvania—Beaver, October 26. District of Columbia—Washington, October 22. North Carolina—Mount Mitchell, October 1.Georgia—Dalton, October 30, Alabama—Birmingham, October 25. Florida—Pensacola, November 4. Cuba—Habana, November 10.
Early dates of fall arrival are: Wyoming—Laramie, August 28. South Dakota—Lennox, August 30. Kansas—Topeka, August 29. Wisconsin—Delavan, August 19. Illinois—Glen Ellyn, August 17. Missouri—Monteer, August 20. Ohio—Toledo, August 19. Tennessee—Knoxville, September 15. Arkansas—Hot Springs, September 19. Louisiana—Monroe, September 14. Mississippi—Gulfport, September 5. Vermont—Woodstock, August 22. Massachusetts—Lexington, August 11. Pennsylvania—Jeffersonville, August 27. District of Columbia—Washington, August 31. Virginia—Salem, August 23. North Carolina—Blowing Rock, September 1. Georgia—Atlanta, September 9. Alabama—Leighton, September 17. Florida—Fort Myers, September 20. Cuba—Habana, October 13. Guatemala—Huehuetenango, September 11. Nicaragua—Río Escondido, October 24. Costa Rica—San José, September 17. Panamá—New Culebra, October 24. Colombia—Santa Marta Region, October 14.
Casual records.—In 1898 an adult male of this species was found dead at Narssag, Greenland. In Bermuda one was seen on March 2, 1914, and it remained about six weeks.
Egg dates.—Alberta: 6 records, June 1 to 16.
New Brunswick: 82 records, June 10 to July 10; 46 records, June 17 to 26, indicating the height of the season.
Quebec: 30 records, June 8 to 29; 21 records, June 17 to 27.
VERMIVORA CELATA CELATA (Say)
EASTERN ORANGE-CROWNED WARBLER
HABITS
The type race of the orange-crowned warbler makes its summer home in northwestern Canada and Alaska, from northern Manitoba to the Kowak River, migrating in the fall southeastward through the United States to its winter range in the southern Atlantic States and Gulf States, from South Carolina and Florida to Louisiana. It was discovered and named by Say (1823) early in May at Engineer Cantonment, on the Missouri River, while on its northward migration.
The main migration route is through the Mississippi Valley, northwestward in the spring and southeastward in the fall. It is very rare in spring in the northern Atlantic States, though there are a few records for even Rhode Island and Massachusetts, but there are many fall records for this region, some of them remarkably late. It seems to be rare at either season in Ohio; Milton B. Trautman (1940) gives only 10 records for Buckeye Lake, 5 in spring and 5 in fall. “Eightwere noted in lowlands, within 10 feet of the ground, in dense tangles of blackberry bushes, rosebushes, or grapevines. The remaining 2, both fall birds, were in rather well-drained, brushy, and weedy fields.”
Dr. E. W. Nelson (1887) says of its status in Alaska:
Throughout the wooded region of Northern Alaska, from the British boundary line west to the shores of Bering Sea, and from the Alaskan range of mountains north within the Arctic Circle as far as the tree-limit, this species is a rather common summer resident. It is known along the shores of Bering Sea and Kotzebue Sound mainly as an autumn migrant, as it straggles to the southward at the end of the breeding season. Wherever bushes occur along the northern coast of the Territory it is found at this season, and at Saint Michaels it was a common bird each summer from the last of July up to about the middle of August, after which it became rare and soon disappeared. I have never noted it on the seacoast during the spring migration.
The Prebles (1908) found it well distributed and probably breeding throughout the Athabaska-Mackenzie region. MacFarlane (1908) found it breeding as far north as the Anderson River. Kennicott, according to Baird, Brewer, and Ridgway (1874), found it nesting about Great Slave Lake. And Ernest Thompson Seton (1891) reported it as a common summer resident and breeding near Carberry, Manitoba.
Nesting.—Herbert Brandt (1943) found two nests of the eastern orange-crowned warbler along the Yukon River in Alaska, about 20 miles up from the sea, on July 1, 1924. His first nest contained five eggs, advanced in incubation. The nest was near the bank of the river, “in a bush 18 inches from the ground. The nest was loosely made of coarse grass held together with bark strips, silvery plant down, and a few feathers, one of which was a mottled feather of the Northern Varied Thrush. Twenty feet away was another nest of the same species, which held three young just hatched and two pipped eggs.* * *The measurements of the two nests cited are: height, 2.25 to 3.00; outside diameter, 3.5; inside diameter, 1.75; and depth of cup, 1.50 to 1.75 inches.”
MacFarlane’s (1908) nests, found on the Anderson River, “held from four to six eggs each, and they were made of hay or grasses lined with deer hair, feathers and finer grasses, and were usually placed in a shallow cavity on the ground in the shade of a clump of dwarf willow or Labrador tea.”
Baird, Brewer, and Ridgway (1874) write:
The nests of this species, seen by Mr. Kennicott, were uniformly on the ground, generally among clumps of low bushes, often in the side of a bank, and usually hidden by the dry leaves among which they were placed. He met with these nests in the middle of June in the vicinity of Great Slave Lake. They were large for the size of the bird, having an external diameter of four inches, and a height of two and a half, and appearing as if made of two or three distinctfabrics, one within the other, of nearly the same materials. The external portions of these nests were composed almost entirely of long, coarse strips of bark loosely interwoven with a few dry grasses and stems of plants. Within it is a more elaborately interwoven structure of finer dry grasses and mosses. These are softly and warmly lined with hair and fur of small animals.
E. A. Preble (1908) reported a nest found near Fort Resolution that “was placed among thick grass on a sloping bank, and was composed outwardly of grass andEquisetumstems, with a layer of finer grass and with an inner lining of hair.”
Several nests have been reported from points farther south as being of this warbler, but these are probably all referable to the Rocky Mountain subspeciesVermivora celata orestera.
Eggs.—The orange-crowned warbler lays from 4 to 6 eggs to a set, probably most often 5. Dr. Brandt (1943) describes his Alaska eggs as follows: “The egg is short ovate in outline, the surface moderately glossy, and the shell delicate. The ground color is white and is prominent because the markings obscure but one-fifth of its area. These spots are very small, and are peppered over the broad end in an ill-defined wreath, while over the smaller two-thirds the egg is almost immaculate. In color the markings range from hydrangea red to ocher red; and underlying these are a few weak spots of deep dull lavender.” Probably a series of the eggs would show all the variations shown in eggs of the other races. The measurements of 50 eggs, including those of the Rocky Mountain race, average 16.2 by 12.7 millimeters; the eggs showing the four extremes measure18.3by 13.2, 17.0 by14.2, and14.7by12.2millimeters (Harris).
Plumages.—Dr. Dwight (1900) describes the juvenal plumage as “above, brownish olive-green. Wings and tail olive-brown, broadly edged with bright olive-green, the median and greater coverts tipped with buff. Below, greenish buff paler and yellower on abdomen and crissum. Lores and auriculars grayish buff.”
The first winter plumage is acquired by a postjuvenal molt that involves the contour plumage and the wing coverts but not the rest of the wings or the tail. The sexes are alike in the juvenal plumage and much alike in all plumages, except that the female is always duller; in her first winter plumage the orange crown is lacking, and it is more or less suppressed and sometimes wholly lacking in subsequent plumages. Dr. Dwight (1900) describes the young male in first winter plumage as “above, bright olive-green, mostly concealed on the pileum and nape with pale mouse-gray edgings that blend into the green. The crown brownish orange concealed by greenish feather tips. Wing coverts broadly edged with dull olive-green, sometimes the greater coverts with faint whitish tips. Below, pale olive-yellow, grayish on the chin and sides of neck with very indistinct olive-gray streaking.A dusky anteorbital spot. Lores, orbital ring and indistinct superciliary stripe mouse-gray.”
The first nuptial plumage is acquired by a partial prenuptial molt, “which involves chiefly the anterior part of the head and the chin. A richer, half concealed, orange crown patch is acquired; the lores and adjacent parts become grayer, the anteorbital spot darker. Wear makes birds greener above and slightly yellower below. Young and old become practically indistinguishable.”
Subsequent molts consist of a complete postnuptial molt in summer and a partial prenuptial molt in early spring, as described above. The adult winter plumage “differs chiefly from first winter dress in possessing a larger, more distinct crown patch,” in the male, and more or less of it in the female. “The color below is uniform and paler.”
Food.—Nothing seems to be known about the summer food of the orange-crowned warbler, but it probably does not differ greatly from that of the lutescent warbler, whose food has been more thoroughly studied. In winter, it probably eats a fair proportion of berries and other fruits, especially when it spends the winter somewhat farther north than insects are to be found in abundance. It has also been known to come to a feeding station and eat suet, peanut butter, and doughnuts. In summer, it is probably almost wholly insectivorous. I can find no evidence that it does any damage to grapes or other cultivated fruits on its fall migration.
Voice.—Ernest Thompson Seton (1891) says of an orange-crowned warbler that he shot in Manitoba on May 12, 1883: “It was flitting about with great activity among the poplar catkins, and, from time to time, uttering a loud song like 'chip-e chip-e chip-e chip-e chip-e.' On May 141 shot another Orange-crowned Warbler. Its song is much like that of the Chipping Sparrow, but more musical and in a higher key. The bird is extremely restless and lively, moving about continually among the topmost twigs of the trees and uttering its little ditty about once in every half minute.”
Dr. Lynds Jones wrote to Dr. Chapman (1907): “The song is full and strong, not very high pitched, and ends abruptly on a rising scale. My note book renders itchee chee chee chw’ chw'. The first three syllables rapidly uttered, the last two more slowly. One heard late in the season sang more nearly like Mr. Thompson’s description:chip-e, chip-e, chip-e, chip-e, chip-e, but with the first vowel changed toe, thus eliminating what would appear to be a marked similarity to the song of Chippy. Even in this song the ending is retained.”
Francis H. Allen tells me that this warbler “has achipnote suggesting that of the tree sparrow but sharper.”
Field marks.—The orange-crowned warbler is a plain bird, with practically no white markings in wings or tail, clad in dusky olive-green,paler below, the underparts sometimes obscurely streaked with olive-gray. The brownish orange crown patch is usually not conspicuous, except in worn summer plumage, and lacking in young birds and some females.
Fall.—Orange-crowned warblers begin to leave northern Alaska in August. Dr. Nelson (1887) says that it is rare about St. Michael after the middle of the month, his latest date being August 24. The birds obtained at that season were mainly young of the year. “In fall this species frequents the vicinity of dwellings and native villages, where it searches the crevices of the fences and log houses for insects.”
The southeastward migration through central Canada and the United States seems to be leisurely and quite prolonged, mainly in September and early October, but often continuing into November. In Massachusetts, there are numerous late fall records and some winter records. Horace W. Wright (1917) has published an extensive paper on this subject and has collected the following Massachusetts records: “Mr. Brewster’s eleven records lie within the period of autumn from September 23 to November 28. There are three for September, namely, the 23rd and the 30th twice; none for October; and eight for November, namely, 7th, 9th, 10th, 17th, 20th-21st, 23rd-24th, 25th, and 28th. On two occasions two birds were present, November 9 and 28. My own records run later. The earliest is November 5, and the latest is January 23. They are November 5, 18, 20, 22, 28, 29, January 10, 19, 23.” As Mr. Wright’s records cover a period of 8 years ending with January 1916, they indicate that the orange-crowned warbler is not such a rare straggler in Massachusetts as is generally supposed, and may be looked for almost any year in late fall, or even winter. Mr. Forbush (1929) says of its occurrence there:
This warbler may be found almost anywhere in New England during the fall migration wherever there are trees and shrubbery. In my experience the bird has been either in the trees or in the tops of rather tall shrubs and never very high, but like other members of the genus, though it nests on the ground it is said to spend considerable time in the upper parts of trees. It seems fond of the edges of woodlands near water, but it also frequents open woods, orchards, fruit gardens and shade trees, where amid the foliage it is very seldom noticed by the ordinary observer. When approached it divides its attention between the observer and its insect prey, which it hunts assiduously in the manner of others of the genus. This warbler may be seen rarely in small companies, but more often singly or in company with a small group of warblers of other species.
Dr. Winsor M. Tyler contributes the following: “The orange-crowned warbler is a rare bird in New England, but we may look for it with some hope of success in the very late autumn, through November and even into December, during the soft, calm days of Indian Summer. As we walk along over the dead leaves, wet from last night’s frost, watching for the bird in the shrubs by the roadside and in neglectedpastures, almost the only sound is the ticking of the falling leaves as they hit against the branches; and mistiness is all about us. Several seasons may pass before we hear its sharpchip, which stands out clearly from the gentle voice of the late-lingering myrtle warblers, and see it flitting all alone among the twigs, or on the ground—a lonely, dark, obscure little bird, darker and more deliberate than the kinglets. It is strange that aVermivorashould linger here with winter so near at hand, but indeed there is evidence which leads us to believe that a few of these warblers may attempt to spend the winter in the southern part of this region, and should any one of them withstand the cold season, it may furnish, when it moves northwards towards its breeding ground, one of the exceedingly rare instances of the occurrence of the bird on the northern Atlantic coast in spring.”
Winter.—The principal winter home of the orange-crowned warbler seems to be in the southern Atlantic and Gulf States. Of its occurrence in coastal South Carolina, Arthur T. Wayne (1910) writes: